This study, done in collaboration with investigators in the Division of Cancer Etiology was designed to detect the effects of cancer and its treatment on childhood patients who survived to adulthood as well as any effects that might have been transmitted to their offspring. Specific issues for investigation were the occurrence of subsequent primary cancers, quality of life, late morbidity other than cancer and infertility among the cases and cancer and birth defects among offspring. Cases were selected from 5 U.S. cancer registries that had a histologically confirmed malignant neoplasm or brain tumor diagnosed under age 20 years, between 1945 and 1974, who survived at least 5 years after diagnosis, and who reached the age of 21 years. Up to 2 sibling controls were selected for each case with sequential priority given to full blood relationship, same sex, closest in age. Interviewer administered questionnaires were obtained for 2285 (91%) of cases and 3265 (91%) of controls. Surviving cancer patients more often than their sibiling controls reported never having initiated a pregnancy; 45% versus 29% for survivors and controls respectively. Among subjects who reported a pregnancy, the average number of pregnancies was 2.42 for survivors and 2.66 for controls. There were no differences between the groups in the rates of miscarriage (11.1% and 11.5% respectively), still births (0.8% in both groups) or ectopic pregnancies (0.6% and 0.5%).